This invention relates to an improved modular exterior rearview mirror assembly incorporating an electronic control module. More particularly, the present invention relates to the mounting of the electronic control module within the exterior rearview mirror assembly housing.
Conventional exterior rearview assemblies include a mirror housing and a reflective element supported in the housing by a mirror actuator for engaging the reflective element for adjusting the reflective element's orientation. Typically, the mirror actuator is controlled either manually by a lever inside the vehicle or electrically by a switch inside the vehicle. In recent developments, mirror assemblies may include mirror actuators responsive to memory devices that store multiple positions for the mirror assembly's reflective element, such as disclosed in U.S. Pat. No. 5,196,965 to Lang et al. entitled REAR VIEW UNIT FOR MOTOR-VEHICLES, which is incorporated by reference herein. Furthermore, mirror assemblies may include: Electro-optic reflective elements, which adjust the reflectance level of the reflective element; remote-actuated exterior vehicle security lights and signal lights, such as disclosed in commonly assigned U.S. Pat. Nos. 5,371,659 and 5,497,305 for REMOTE ACTUATED EXTERIOR VEHICLE SECURITY LIGHT; Global Positioning System antennas or receivers, as disclosed in patent application Ser. No. 08/569,851 filed Dec. 8, 1995, by Roger L. Veldman and Desmond J. Farrell for a VEHICLE GLOBAL POSITIONING SYSTEM NAVIGATION AID; heaters to remove ice from the reflective element, such as disclosed in U.S. patent application Ser. No. 07/971,676, filed Nov. 4, 1992, by Niall R. Lynam et al. for AN ELECTROCHROMIC MIRROR FOR VEHICLES, now U.S. Pat. No. 5,446,576; and blind spot detection systems, such as disclosed in U.S. patent application Ser. No. 60/013,941 filed Mar. 22, 1996, by Kenneth (NMI) Schofield for PROXIMITY DETECTION OF OBJECTS IN AND AROUND A VEHICLE, now U.S. Pat. No. 5,786,772, the disclosures of which are hereby incorporated herein by reference. Various other devices housed in an exterior mirror assembly include heading sensors, intrusion detectors, variable reflectance control systems for electrochromic mirror operation, transmitting and/or receiving antennas, such as antennas for global positioning systems (GPS) and intelligent vehicle highway systems (IVHS), garage door opener transmitters and antennas, cellular telephone transmitters and antennas, and the like are candidates for positioning within a mirror assembly. For example, an electronically trainable garage door opener may be included, such as is described in U.S. Pat. No. 5,479,155 issued to Zeinstra et al.
The increase in electronic functions being performed through the vehicle rearview assembly increasingly involves communication with other portions of the vehicle. For example, global positioning system (GPS) functions and intelligent vehicle highway system (IVHS) functions may interact with other modules controlling vehicle navigation and the like. A headlamp control of the type disclosed in commonly assigned U.S. patent application Ser. No. 08/277,674 filed Jul. 19, 1994, by Kenneth L. Schierbeek and Niall R. Lynam, for an AUTOMATIC REARVIEW MIRROR SYSTEM WITH AUTOMATIC HEADLIGHT ACTIVATION, now U.S. Pat. No. 5,715,093, the disclosure of which is hereby incorporated herein by reference, utilizes common light sensors for activating the vehicle's headlights and establishing a partial reflectance level for an electro-optic mirror element. Such features may require interaction between the mirror assembly and a headlamp module.
The vehicular exterior mirror assembly has become sophisticated resulting in a more complicated assembly having a plurality of electrical components and electronic controls. Frequently, the electrical components and electronic controls are separately installed and, quite often, commonly mounted to the reflective element. This is especially common where an electrical function associated with the reflective element is performed. For example, in patent application Ser. No. 08/316,047, filed Sep. 30, 1994, by Kenneth L. Schierbeek et al., entitled MODULAR VARIABLE REFLECTANCE MIRROR ASSEMBLY, now U.S. Pat. No. 5,659,423, the disclosure of which is hereby incorporated herein by reference, two generally rearwardly directed light sensors are mounted, along with a mirror reflectance level control circuit to the back of the reflective element. Hence, the overall weight of the mirror assembly is significantly increased but without a corresponding increase in the stiffness to its supporting structure. This may result in a mirror actuator assembly and reflective element with a lower natural frequency, which subjects the mirror actuator assembly to increased vibration. This increased vibration can induce unwanted distortion in the reflected image in the reflective element and may shorten the service life of the various components subjected to the vibration.
Furthermore, as the number of components and controls increase the amount of available space within the housing to accommodate all these components and controls is becoming increasingly limited. Moreover, since a large number of the components are installed on the back of the mirror actuator assembly, servicing of the mirror actuator assembly is more difficult. Typically each component requires removal in order to access the components within the mirror actuator assembly housing.
Accordingly, there is a need for an exterior mirror assembly that is not as susceptible to vibrations. There is also a need for an exterior mirror assembly that provides more space for the many electrical components and electronic controls that are desirable in today's sophisticated exterior mirror assembly. Moreover, there is a need for a mirror assembly that is easier to assemble and service.